import sys



# str = sys.stdin.readline()
# print(str)
#
# num = input("请输入第一个数字：")
# print(num)
#
# sys.stdout.write('hello')
# print('world')

# file = open('a.txt','r',encoding='utf-8',buffering=1)
# print(file.read())
# file.close()
#
#
# with open('a.txt','r',encoding='utf-8',buffering=1) as file2:
#     print(file2.readlines())

with open('a.txt','a',encoding='utf-8',buffering=1) as file3:
    file3.write('hello world')
    